Some offshore resource recovery activities, e.g., withdrawal of hydrocarbon fluids from a subsurface reservoir through a well tubular and riser assembly to surface fluid delivery facilities, have previously been accomplished using an offshore platform. The offshore platform typically supports at least a portion of the riser and fluid delivery facilities and other equipment needed to process and recover resource fluids.
For shallow water depth locations, a well and fluid delivery system typically includes a riser with the remainder of the fluid delivery system generally located on a rigid platform structure fixed to a seafloor anchor or foundation. For deepwater offshore platforms locations, e.g., offshore platforms located in waters having a depth exceeding about 1,500 feet (or about 457 meters), this type of fixed tower structure is typically not cost effective, and other types of facilities may be used, e.g., subsea wellheads and delivery systems.
As the distance between the subsea wellheads and surface processing facilities increases, e.g., due to increasing water depths, the addition of external energy to the recovered fluids may become necessary to recover commercial quantities of oil or other fluids from deepwater reservoirs. For wells in deepwater locations, especially in ultra deepwater locations (herein defined as water surface to mudline depths of at least about 10,000 feet or 3,000 meters), the addition of external energy may extend the working range of reservoir pressures that can be produced. The additional external energy can be a major factor in producing commercial flowrates of oil and gas from these deepwater or ultra-deepwater resources.
One of the items of equipment that may be required to process and recover commercial quantities of oil and/or gas from deep, multi-phase reservoirs is a pump. The pump must be able to handle multi-phase fluids such as oil with lighter hydrocarbon or inert gases, oil with steam or flashing hot brine, slurries, or other fluid-like mixtures of components having density differences.